1. Field of the Invention
The presently disclosed and/or claimed inventive process(es), procedure(s), method(s), product(s), result(s), and/or concept(s) (collectively hereinafter referred to as the “presently disclosed and/or claimed inventive concept(s)”) relates generally to processes and systems for hydroprocessing biopyrolysis oils. More specifically, the presently disclosed and/or claimed inventive concept(s) relates to the rejuvenation of an at least partially flow constricted biopyrolysis oil hydroprocessing reactor(s).
2. Description of the Related Art
With the rising costs and environmental concerns associated with fossil fuels, renewable energy sources have become increasingly important. The development of renewable fuel sources provides a means for reducing the dependence on fossil fuels. Accordingly, many different areas of renewable fuel research are currently being explored and developed.
With its low cost and wide availability, biomass has increasingly been emphasized as an ideal feedstock in renewable fuel research. Consequently, many different conversion processes have been developed that use biomass as a feedstock to produce useful biofuels and/or specialty chemicals. Existing biomass conversion processes include, for example, combustion, gasification, slow pyrolysis, fast pyrolysis (with and without a catalyst), liquefaction, and enzymatic conversion. The product produced from the fast pyrolysis of biomass is a liquid product commonly referred to as “biopyrolysis oil”. Biopyrolysis oil may be processed into transportation fuels, hydrocarbon chemicals, and/or specialty chemicals.
Biopyrolysis oils are generally less stable than petroleum derived hydrocarbons. This instability is associated with bimolecular reactions of oxygen-containing compounds, such as condensation and/or polymerization reactions. At the typical elevated reactor temperatures of biopyrolysis oil hydroprocessing reactors (such as 300-800° F.), these instability reactions become more pronounced resulting in heavier compounds which create deposits in the biopyrolysis oil hydroprocessing reactors. In order to minimize such fouling in commercial operations, biopyrolysis oil hydroprocessing reactor temperatures are kept as low as possible while still sufficiently high to provide effective hydrodeoxygenation. However, even with such temperature control, there is still significant fouling requiring frequent and costly unit shutdowns for deposit removal, hydroprocessing catalyst regeneration, and/or hydroprocessing catalyst replacement. Accordingly, there remains a need for an improved and efficient process for rejuvenating an at least partially flow constricted biopyrolysis oil hydroprocessing reactor.